drm/radeon: fix MC blackout on evergreen+
drm/radeon: fix MC blackout on evergreen+

Force the crtc mem requests on/off immediately rather
than waiting for the double buffered updates to kick in.
Seems we miss the update in certain conditions.  Also
handle the DCE6 case.

Signed-off-by: Christopher Staite <711c73f64afdce07b7e38039a96d2224209e9a6c@yourdreamnet.co.uk>
Signed-off-by: Alex Deucher <08dc22c6156113f2deff178e35e3ed9b24d6af9e@amd.com>
Cc: 4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs